Orac over at Respectful Insolence has a great post on skepticism and scientific consensus, discussing the assertion that skeptics always side with scientific consensus. He talks about how cranks and denialists tend to cherry-pick their evidence and are usually strongly emotionally motivated, to the point that their subjectivity overwhelms their objectivity.

He has this to say about global warming:

But what about consensuses that are strong but not as bullet-proof, usually because, although there is a consensus, there are fairly wide error bars around the predictions or uncertainty regarding the importance of various factors? The prototypical example of this is anthropogenic global warming, for which there is a strong consensus among climate scientists but still a fair amount of uncertainty about the outcome.

Right. I wouldn't consider myself a global warming denialist. I do think the average global temperature is increasing, and I think a significant contributing factor to that warming is human activity. What I am skeptical about with regard to global warming are causal links to specific events (like Hurricane Katrina or the California wildfires) and some of the more dire near-term predictions, such as those on the Inconvenient Truth website:

Deaths from global warming will double in just 25 years -- to 300,000 people a year.

Global sea levels could rise by more than 20 feet with the loss of shelf ice in Greenland and Antarctica, devastating coastal areas worldwide.

Heat waves will be more frequent and more intense.

Droughts and wildfires will occur more often.

The Arctic Ocean could be ice free in summer by 2050.

More than a million species worldwide could be driven to extinction by 2050.

Some of these have hedge terms like "could," but others, like the first, are proclamations. Their source? The World Health Organization, but they don't list a document or link that might contain this information. They're not saying that 150,000 more people "might" die a year due to global warming...they're saying they "will." It's this kind of stuff I'm skeptical about.

Back to Orac:

Thus, being skeptical of the consensus is not the mark of the crank. It's how and why that skepticism exists that distinguishes crankery from genuine scientific skepticism. We should not forget that.

Well, first of all, I'm not even sure that widespread catastrophe due to global warming is the scientific consensus. I would hope that most environmental scientists, like most scientists in general, are cautious about making large-scale predictions about the behavior of complex systems that are incredibly difficult to model. If that is the consensus, then it's not that I disagree, I'm just highly skeptical that the sky is necessarily falling.

So what are my motivations? Do I own stock in the oil companies or something? Well, no. Actually, I think the best argument for weaning ourselves off fossil fuels has less to do with global warming, or the fact that those sources are limited. I'm in favor of the US building many more nuclear power plants and becoming less dependent on fossil fuels based on political reasons. I want to see us end (or at least limit) our dysfunctional dependency on Middle Eastern oil.

I'm also generally skeptical of predictions that the sky is falling. I remember reading quite a bit about dire predictions of overpopulation from the 60's and 70's. Supposedly we were all going to starve by now.

Now, I'm not glibly dismissing the possible ramifications of global warming. I just think the predictions, which are highly unlikely to be very firm, are being exaggerated, and I'd probably trust the science more if it were being hyped less.

In the meantime, I think we have bigger fish to fry, and I personally don't think global warming even makes the top ten in terms of critical issues facing humankind. When I'm blogging from North Dakota because all the land at my latitude is a scorched, unlivable desert, I suppose I'll eat my words. Until then I'll remain skeptically yours.